2 research outputs found
Possible influence of the convection schemes in regional climate model RegCM4.6 for climate services over Central Africa
AbstractIn this study we evaluate the reliability of the Regional Climate Model (RegCM4.6) by performing several sensitivity tests at 50 km horizontal resolution using 10 convection schemes or combination of convection schemes. Emphasis on model output is made for the SeptemberâOctoberâNovember 2017â2019 seasonal period. Part of the Central African region, five subâregions, was identified. The simulated temperatures are compared to the daily climatology of nearâsurface temperature of the European Centre for MediumâRange Weather Forecasts Reanalysis fifthâgeneration and the National Center for Environmental Prediction datasets, while the simulated precipitations are compared to the precipitation of the Global Precipitation Climatology Project and Climate Hazards Group Infrared Precipitation with Stations datasets. In most analyses, the Grell scheme with ArakawaâSchubert closure assumption tends to have the best index of agreement but its spatial distribution shows underestimation of rainfall. Generally, the Emanuel convection scheme is more suitable to represent rainfall and temperature over Central Africa. Compared to our previous study (Komkoua Mbienda et al., International Journal of Climatology, 2017, 37, 328â342), the present study shows that we have to pay attention to the choice of convective scheme when using any version of RegCM4 released for climate study over Central Africa. This choice is strictly related to the RegCM version released, the study years and the season. It is important to note, however, that the results presented are a preliminary study of the response to the selected convection schemes. The analysis uses a limited sample of climate model simulation (three model years for each convection scheme). Followâup work, featuring longer duration climate simulations and a full assessment of statistical significance, is therefore required to confirm the robustness of the analysis presented
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Strengthening weather forecast and dissemination capabilities in Central Africa: Case assessment of intense flooding in January 2020
The first dekad of January 2020 was characterised by heavy precipitation in the capital of the Republic of Congo, Brazzaville, which led to several localised landslides. Satellite-derived rainfall estimates and rain-gauge totals illustrate a strong wet spell between the 6th and 9th January 2020 across southern Congo. This study highlights the generation and implementation of user-driven weather and climate forecast bulletins, developed at the Economic Communities of Central African States (ECCAS) Climate Application and Prediction Centre (CAPC), to reduce the impacts associated with intense precipitation during this dekad. Through doing so, we document the current state of regional-scale climate services across Central Africa. Advisories and outlooks generated by CAPC use risk matrices developed by the World Meteorological Organisation (WMO) and are produced at hourly, daily, sub-seasonal, and seasonal timescales. To develop them, meteorologists and climate scientists at CAPC combine information from a wide range of meteorological observations and forecasts. Regional-scale forecasts are downscaled to individual countries to improve accessibility and relevance.Central African users have reported that bulletins provide support for mitigating against the impacts of extreme weather and have requested more reliable sub-seasonal and seasonal forecast products. In this paper we take the opportunity to discuss the resources obtained through the Satellite and Weather Information for Disaster Resilience (SAWIDRA) framework, which are often taken for granted in developed nations, including the procurement of a high performance computing system, satellite data and numerical models outputs receiving stations. This study is the first to highlight the current state of regional-scale climate services across Central Africa and motivates further co-production of climate services across the region